This invention relates to an electronic timepiece in which a time count operation is effected using a shift register and an error arising from the oscillation frequency of a reference oscillator is corrected by a control system of the shift register.
An electronic timepiece is conventionally known in which a time count operation is effected based on an oscillation signal from the reference oscillator which is constituted of a crystal oscillator of stable oscillation. A digital display type electronic timepiece of this variety is also proposed in which a time display is effected in a digital mode. In particular, a digital display type electronic timepiece becomes known in which a display is effected by an electronic signal which is derived from a liquid crystal, LED etc.
In such electronic timepiece, the oscillation signal from the reference oscillator is properly frequency divided into time count signals corresponding to time display units such as "hours", "minutes", "seconds" etc, and a time display is made by controlling the numerals display function corresponding to each time unit by the time count signal. Such electronic timepiece has a great advantage in that a correct time count operation is always effected by stably setting the oscillation frequency of the reference oscillator at all times. Although the stabilization of the oscillation frequency can be attained using, for example, a crystal oscillator, it is further necessary that in order to continue a correct time count operation the oscillation frequency of the reference oscillator be set to a standard frequency determined in connection with a time count circuit section. That is, it is necessary to correct an error as produced between the standard frequency and the oscillation frequency of the reference oscillator. Such a reference oscillator is equipped with a fine adjustment mechanism for adjusting the oscillation frequency by a trimmer capacitor etc. However, providing such a trimmer adjustment mechanism with respect to the reference oscillator and adjusting it manually will involve a great increase in an amount of task during the assembly and adjustment process of the timepiece, thus imparting a very adverse effect to the operability and quantity production.